const express = require('express')
const app=new express()
const bp=require('body-parser')
app.use('/hello',function(req,res,next) {
	console.log("第一层");
    next()
})
app.use('/hello',function(req,res,next) {
	console.log("第二层");
	res.send('hello')
})
app.listen(3001)